xtime.h

/* xtime -- extended-resolution integer time stamps Copyright (C) 2005, 2006 Free Software Foundation, Inc. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. *//* Written by Paul Eggert. */#ifndef XTIME_H_# define XTIME_H_ 1/* xtime_t is a signed type used for time stamps. It is an integer type that is a count of nanoseconds -- except for obsolescent hosts without sufficiently-wide integers, where it is a count of seconds. */# if HAVE_LONG_LONG_INTtypedeflonglongint xtime_t;
# define XTIME_PRECISION 1000000000# else# include <limits.h>typedeflongint xtime_t;
# if LONG_MAX >> 31 >> 31 == 0# define XTIME_PRECISION 1# else# define XTIME_PRECISION 1000000000# endif# endif/* Return an extended time value that contains S seconds and NS nanoseconds, without any overflow checking. */staticinline xtime_t
xtime_make (xtime_t s, longint ns)
{
if (XTIME_PRECISION == 1)
return s;
elsereturn XTIME_PRECISION * s + ns;
}
/* Return the number of seconds in T, which must be nonnegative. */staticinline xtime_t
xtime_nonnegative_sec (xtime_t t)
{
return t / XTIME_PRECISION;
}
/* Return the number of seconds in T. */staticinline xtime_t
xtime_sec (xtime_t t)
{
return (XTIME_PRECISION == 1
? t
: t < 0
? (t + XTIME_PRECISION - 1) / XTIME_PRECISION - 1
: xtime_nonnegative_sec (t));
}
/* Return the number of nanoseconds in T, which must be nonnegative. */staticinlinelongint
xtime_nonnegative_nsec (xtime_t t)
{
return t % XTIME_PRECISION;
}
/* Return the number of nanoseconds in T. */staticinlinelongint
xtime_nsec (xtime_t t)
{
longint ns = t % XTIME_PRECISION;
if (ns < 0)
ns += XTIME_PRECISION;
return ns;
}
#endif